Bigin Version and Zoho One

Bigin Version and Zoho One

We are a Zoho One subscriber and are looking at a more simplified solution for our sales team. Bigin seems to fit the bill and I thought it was included in Zoho One, but every time I try to do anything complex I'm told I need to upgrade. Is this normal?

For instance, when looking to integrate Email I get the following prompt:

The Email sharing feature is not a part of the Free plan.
Please upgrade to our 'Express' plan to access premium features like this.